1. Field of the Invention
The present invention relates to an engine starting system applied to a propelled object including a vehicle which is propelled by an engine (internal combustion engine) mounted thereon (for example, a two-wheeled vehicle, a four-wheeled vehicle, an all terrain vehicle (ATV), a ship, a jet-propulsion watercraft, or the like), and more particularly to a technique of preventing a battery from running out (a battery voltage from dropping) due to tampering of a switch by a third party, the switch being manually actuated for starting the engine.
2. Description of the Related Art
Conventionally, a vehicle using a portable electronic key (portable equipment) is provided with a starting switch which is manually actuated. For example, in a case of a four-wheeled vehicle, the switch is provided to a door handle or a trunk lid of the vehicle. When the switch is actuated by a driver, the switch communicates with the electric key so as to obtain an ID number from the electric key. The ID number is collated with an ID number registered in a control device (equipment on the propelled object side) installed on the vehicle side, and when the ID numbers coincide with each other, the door lock is released.
Also, in a case of a two-wheeled vehicle, there has been proposed a system capable of reliably protecting the vehicle against theft based on a system similar to that for a four-wheeled vehicle.
For example, there has been disclosed an engine starting system for regularly starting an engine mounted on a propelled object, which includes: equipment on a propelled object; a switch; portable equipment; steering unlocking section; power activating section; and an engine control unit, the equipment on a propelled object transmitting, in response to an actuation signal from the switch, an inquiry signal including a collation code to the portable equipment, the portable equipment transmitting an answer signal including a cipher code corresponding to the inquiry signal, the equipment on the propelled object side allowing the engine to start by causing the engine control unit to operate, in a case where the answer signal corresponds to the inquiry signal, by unlocking the steering unlocking section and activating the power activating section, in which the equipment on the propelled object side executes an unlocking operation of the steering unlocking section, an operation to turn ON the power activating section, or a cranking operation by the engine control unit (refer to, for example, JP 2006-137338 A).
When the conventional engine starting system is applied to a two-wheeled vehicle, it is necessary to take countermeasures against tampering more adequately than in the case of a four-wheeled vehicle. In particular, in a case of a conventional mechanical key cylinder, there has been adopted a mechanism capable of preventing the lock from being forced open with a screw driver or preventing a key inserting hole from being stuffed with a foreign object or being operated. Even in a case of an electronic key, operating an activation switch provided outside of a vehicle leads to start collating IDs with portable equipment, and therefore it is presumed that the switch is repeatedly pushed by a third party. When the switch is actuated by being pushed by a third party, equipment on a propelled object side is activated and transmits radio waves in order to communicate with the portable equipment side. Accordingly, the equipment transmits radio waves every time the switch is actuated even if the portable equipment of the vehicle does not exist, and therefore the battery is consumed and several amperes of current flows therethrough. Therefore, if the switch is tampered and actuated too many times, it may leads to a problem that the battery is made impossible to start the engine due to a power supply voltage drop, that is, the battery runs out.
There has also been a problem that a radio wave transmission portion becomes overheated due to the repetitive actuation of the switch, which leads to a deterioration of a circuit and a failure of the engine starting system.